I used to trade options and had about 99.5% success on all my trades The problem is the 0.5% of the time, it erases all the gains made on the successful ones. I'm convinced without information edge or some capital sunk cost edge (for HFT) you are literally just flipping coins when it comes to trading. What's dangerous is fixation on strategies that form after a period of success. All in all, I think just buying stock…
This doesn't make sense. If you had a 99.5% success rate, you could simply use a fixed $ stop and clean up. I agree you need an information edge, but the difficulty of finding one inversely correlates with your scale. Buying and holding is the best strategy for almost everybody - but that is orthogonal to whether trading is a "coin flip" vs mining an edge.
More generally, there is no optimal amount of stop loss. It ultimately gets auto-stopped out at 3:30 pm, although by then it could have gone nearly to zero anyway. Either the strategy works or it doesn't, and with Trump manipulating the market on random days with significant news, it increasingly doesn't.